A photo posted by Kim Kardashian West (@kimkardashian) on Oct 29, 2014 at 9:23am PDT

While the famous sisters are "obsessed" with the devices, customer Sara Hawes is not so satisfied. She filed the $5 million class action suit against the Florida-based company for deceptive marketing tactics.

According to court documents obtained by The Daily Mail, the Waist Gang Society claims its products "actually burn fat and control the user's weight. This is completely false and misleading. The Products have absolutely no effect on fat loss of the user."

The lawsuit demands an end to the company's weight loss claims, The Daily Mail reported.

In a prior interview with Health about waist training, Caroline Apovian, M.D., a professor of medicine at Boston University School of Medicine and a spokesperson for the Obesity Society, pointed out that there's no evidence wearing a corset triggers fat loss and reshapes the body. "In my opinion, that is complete nonsense," she said.

Waist Gang Society has yet to issue a public statement in response to the suit.

When it comes to whittling your middle, the healthiest approach remains the old-fashioned way: Proper nutrition plus moderate- to high-intensity exercise, and hard work in the form of ab-sculpting core exercises. You can't go wrong with these six belly-flattening moves from celebrity trainer Jennifer Cohen.